DE102011086053A1 - Rotation transmission device for coupling device of crankshaft pulley for drive train of motor vehicle, has electromagnet including armature for limiting movement of slip rings or brushes in axial direction - Google Patents

Abstract

The device (1) has slip rings (8, 9) brought into contact with brushes (24, 25) for temporary transfer of supply voltage between a fixed device (4) and a rotating device (6), where the movement of the slip rings or the brushes is limited in axial direction by an armature (20) of an electromagnet (10). The slip rings and the brushes are biased away from each other by a spring, where the slip rings are arranged concentrically. The electromagnet includes a coil (14) parallel to the slip rings. A lubricating layer is arranged between a yoke (12) and the armature of the electromagnet. An independent claim is also included for a crankshaft pulley for transmitting torque between a crankshaft and a belt drive.

Description

The invention relates to a rotation transmission device for temporarily transmitting a supply voltage between a fixed fixed device and a rotatable relative thereto rotatable means, and with slip rings, which can be temporarily brought to transfer the supply voltage with brushes in contact.

From the German patent application DE 40 09 851 A1 and the German utility model DE 92 03 434 U1 brush lifting devices for asynchronous motors with slip-ring rotors are known. The known Bürstenabhebevorrichtungen contain a rotatable actuating ring with brush actuation links, which cause the lever lifting the brush after the slip rings are shorted by axial displacement of a shorting ring.

The object of the invention is to provide a rotary transmission device according to the preamble of claim 1, which is simple in construction and inexpensive to produce. The rotary transmission device according to the invention should preferably allow a low-wear operation of a coupling device, in particular a crankshaft pulley.

The object is achieved in a rotary transmission device for temporarily transferring a supply voltage between a fixed fixed device and a rotatable relative thereto rotating device, and with slip rings, which can be temporarily brought into contact with brushes for transmitting the supply voltage, achieved in that the slip rings or brushes in limited axial displacement and are coupled to an armature of an electromagnet. The term axial refers to a rotation axis of the rotation transmission device. Axial means parallel or in the direction of the axis of rotation. With the aid of the electromagnet, the slip rings and the brushes can be brought into contact in a simple manner in order to transfer the supply voltage as needed. Thereby, the wear of the rotation transmission device can be reduced.

A preferred embodiment of the rotary transmission device is characterized in that the slip rings / brushes are biased by at least one spring means in the axial direction of the brush / slip rings away. By the biasing force of the spring means, the slip rings and the brushes are kept at a distance from each other, so that the supply voltage is not transmitted. Only when the solenoid is actuated, the brushes and the slip rings against the biasing force of the spring means are moved towards each other and brought into contact.

Another preferred embodiment of the rotary transmission device is characterized in that two slip rings are arranged concentrically. The slip rings are preferably designed as annular bodies with a substantially rectangular ring cross-section.

A further preferred embodiment of the rotation transmission device is characterized in that the electromagnet comprises a coil which is connected in parallel to the slip rings. As a result, a simple circuit is created, which is inexpensive to produce.

A further preferred embodiment of the rotary transmission device is characterized in that a sliding layer is arranged between the armature and a yoke of the electromagnet. The sliding layer serves to reduce the coefficient of friction in the contact case. In addition, the sliding layer is used to represent a magnetic air gap, by which an excessive increase in the magnetic attraction force and thus the friction torque is prevented.

Another preferred embodiment of the rotation transmission device is characterized in that a stop limit is provided for the armature of the electromagnet. The stop limit is to prevent that by the electromagnet itself an increased drag torque is generated. As a result, it can be achieved that the sliding contacts, which are only relatively weakly sprung, themselves come into frictional contact, but not the armature and yoke of the electromagnet.

Another preferred embodiment of the rotary transmission device is characterized in that the electromagnet is preceded by a rectifier. The slip rings are preferably interconnected via the rectifier so that the slip rings always attract regardless of the polarity of the current supply. Thus, the slip ring contact is closed even with a counter current.

Another preferred embodiment of the rotary transmission device is characterized in that a wear adjustment for the brush is provided. For this purpose, the brushes can be sprung on their side facing away from the slip rings by contacts.

The invention further relates to a coupling device with a previously described rotary transmission device. In the Coupling device is preferably an electromagnetically actuated separating clutch.

The invention further relates to a crankshaft pulley for transmitting a torque between a crankshaft and a belt drive, with at least one freewheel and a previously described coupling device. The coupling device preferably comprises two opposing friction surfaces in the axial direction. The friction surfaces preferably extend transversely to the axis of rotation of the crankshaft pulley. In the axial direction, the two friction surfaces are arranged opposite, that is, facing away from each other. The coupling device is preferably designed as a dry friction clutch for bridging the freewheel. With twice the friction surface, larger starting torques can be transmitted than with conventional crankshaft pulleys. As a result, a comfort start is made possible in a simple manner.

A preferred embodiment of the crankshaft pulley is characterized in that the friction surfaces are provided on a damping mass, which is designed as a rotatable electromagnet with a coil. The coupling device is electromagnetically actuated via the coil. The execution of the absorber mass as an electromagnet provides the advantage that no additional space is required for the electromagnet.

A further preferred embodiment of the crankshaft pulley is characterized in that the absorber mass designed as an electromagnet is attached to a Tilgermassenträger using a rubber track. For example, a torque required for starting an internal combustion engine is also transmitted via the rubber track, wherein the absorber mass embodied as an electromagnet can only be rotated by a limited angle of rotation relative to the absorber mass carrier. Due to the limited angle of rotation, the rubber track is protected against overloading when starting.

Another preferred embodiment of the crankshaft pulley is characterized in that on the absorber mass designed as an electromagnet and on the absorber mass carrier teeth are formed, which engage with a torsional backlash. The size of the torsional backlash sets the angle of rotation.

A further preferred exemplary embodiment of the crankshaft pulley is characterized in that the toothing extends in the radial direction on the absorber mass carrier, the toothing extending in the axial direction on the absorber mass designed as an electromagnet. As a result, even slight compensation movements in the radial and / or axial direction are possible, as far as the elasticity of the rubber track allows.

Another preferred embodiment of the crankshaft pulley is characterized in that the rotatable transmission body is attached to the absorber mass, and / or that the fixed transmission body is attached to a crankcase. As a result, the absorber mass can be increased in a simple manner. About the fixed transmission body required for energizing the electromagnet current can be supplied in a simple manner.

A further preferred embodiment of the crankshaft pulley is characterized in that the coupling device comprises two anchor body, the rotationally fixed, but are connected in the axial direction limited displaceable with a belt track. The two anchor bodies are preferably mounted directly or indirectly on the belt track with the aid of leaf springs. The designed as a rotatable electromagnet absorber mass with the two friction surfaces can be clamped in the axial direction between the two anchor bodies.

The invention further relates to a drive train of a motor vehicle, as described, for example, in German Offenlegungsschrift DE 10 2007 021 233 A1 is disclosed. The power transmission unit described therein is replaced by the crankshaft pulley according to the invention.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

1 a schematic representation of a first embodiment of a rotation transmission device;

2 a similar representation as in 1 according to a second embodiment;

3 an enlarged view of slip rings and brushes of the rotation transmission device in an unactuated state;

4 the slip rings and brushes off 3 in the actuated state;

5 the slip rings and brushes in a plan view;

6 a similar representation as in 3 according to a further embodiment;

7 the slip rings and brushes off 6 in plan view and

8th a crankshaft pulley with a rotation transmission device according to the invention in longitudinal section.

In 1 is a rotation transmission device 1 with a party 4 and a rotating device 6 shown schematically. At the Festeinrichtung 4 are slip rings for transmitting a supply voltage 8th . 9 appropriate. The festive institution 4 is an electromagnet 10 with a yoke 12 assigned to a coil 14 includes. The sink 14 is with the interposition of a rectifier 15 and a switcher 16 to a voltage source 18 connected. The slip rings 8th . 9 are via the switch 16 also to the voltage source 18 connected.

The yoke 12 with the coil 14 acts with an anchor 20 together, by a springing 21 from the yoke 12 is biased away. If the coil 14 energized, then becomes the anchor 20 of the electromagnet 10 from the yoke 12 dressed. An attack 22 prevents the anchor 20 in contact with the yoke 12 comes.

Two brushes 24 . 25 are about Anfederungen 26 . 27 with the anchor 20 of the electromagnet 10 coupled. When the anchor 20 during energization of the coil 14 on the yoke 12 moved, then the brushes move 24 . 25 on the slip rings 8th . 9 until they come in contact with them. When the brushes 24 . 25 with the slip rings 8th . 9 Having contact, then become an electromagnet 30 to a supply voltage of the voltage source 18 connected.

The electromagnet 30 includes a yoke 31 with a coil 32 passing through lines 37 . 38 as well as the brushes in contact 24 . 25 and slip rings 8th . 9 over the switch 16 from the voltage source 18 is powered. If the coil 32 of the electromagnet 30 energized in this way, then becomes an anchor 34 attracted and comes in frictional contact with the yoke 31 ,

The anchor 34 is about a springing 35 rotatably with a belt trace 36 connected to a crankshaft pulley. The electromagnet 30 with the yoke 31 and the anchor 34 represents a coupling device 40 which is integrated in a crankshaft pulley. The coupling device 40 with the electromagnet 30 is by means of the relatively small electromagnet 10 energized and thereby actuated by the slip rings 8th . 24 and 9 . 25 through the electromagnet 10 be brought into contact.

The coupling device 40 is in particular designed as a disconnect clutch and serves, for example, to enable a stationary air conditioning in a motor vehicle. The separating clutch is closed during operation of the motor vehicle for starting the internal combustion engine by a starter generator. This operating state has a very small proportion of time and occurs only at low relative speeds. Therefore, it is unfavorable in terms of contact wear and drag torque to make the slip rings for torque transmission constantly present.

To solve this problem, it is proposed according to an essential aspect of the invention, the slip rings 8th . 9 the festive institution 4 with the help of the relatively small electromagnet 10 only on demand with the brushes 24 . 25 to bring into contact. Otherwise, the brushes 24 . 25 through the beginnings 26 . 27 at a distance to the slip rings 8th . 9 held. This will be the voltage source 18 both for controlling the electromagnet 30 the coupling device 40 as well as for the electromagnet 10 also used as a magnet for the brushes 24 . 25 the slip rings 8th . 9 referred to as. This provides the advantage that no additional electronic components are needed. The coil of the electromagnet 10 is parallel to the slip rings 8th . 9 connected.

Should it due to a residual magnetization and consequently a residual drag torque of the electromagnet 30 the coupling device 40 it is necessary or useful to energize them for active opening in an opposite direction, this is done via the rectifier 15 allows. The electromagnet 10 is over the rectifier 15 so with the slip rings 8th . 9 interconnects that anchor 20 regardless of the polarity when energizing always attracts and thus the slip ring brush contact 8th . 9 ; 24 . 25 is closed even with a Gegenbestromung.

The air gap in the working area between the anchor 20 and the yoke 12 of the electromagnet 10 is to be chosen so that it moves in the linear range of the magnetic force characteristics in order to keep the tolerance of tolerance with respect to the tightening force low.

In 2 is by a dash 44 hinted that the brushes 24 . 25 even without springing directly to the anchor 20 can be coupled. In this case, the slip rings are 8th . 9 with corresponding Anfederungen 46 . 47 Mistake. The slip rings 8th . 9 are also via a switch 48 to a voltage source 49 connected. This in 2 illustrated embodiment includes no rectifier. Otherwise, this corresponds to 2 illustrated embodiment the in 1 illustrated embodiment.

In the 3 to 5 are slip rings 51 . 52 shown concentric to an axis 54 are arranged. By an arrow 55 is implied that the electromagnet ( 10 in the 1 and 2 ) is unconfirmed, so the slip rings 51 . 52 of brushes 58 . 59 are spaced. The brushes 58 . 59 are designed as brush rings that are concentric to an axis 60 and thus eccentric to the axis 54 are arranged.

The brushes designed as brush rings 58 . 59 represent wear partners and are on their slip rings 51 . 52 opposite sides through contacts 66 . 67 sprung. On the slip rings 51 . 52 facing sides are axial stops 64 . 65 for the brushes 58 . 59 intended. Here are the brushes 58 . 59 in a holder 62 limited displaceable guided in the axial direction. The contacts 66 . 67 are with the interposition of a switch 68 to a voltage source 69 connected.

In 4 is by an arrow 70 indicated that the electromagnet ( 10 in the 1 and 2 ), that is, was pressed to the brushes 58 . 59 with the slip rings 51 . 52 to bring into contact.

In the 6 and 7 It is shown that instead of brush rings also several brush cylinders 73 . 74 can be used. In the illustrated embodiment, three brush cylinders each 73 . 74 evenly over the associated circumference of the slip rings 51 . 52 distributed. The brush cylinders 73 . 74 are partially overlapping to the slip rings 51 . 52 arranged. This will be the brush cylinder 73 . 74 with the help of a radial holder 76 kept in position. The holder 76 has axial stops 77 . 78 for the brush cylinders 73 . 74 on.

In 7 are the brush cylinders 73 . 74 partly outside the slip rings 51 . 52 arranged. Alternatively, the brush cylinders may also be partially radially within the slip rings 51 . 52 to be ordered. To optimize the space, it is also possible to use the brush cylinders 73 partially radially outside the slip ring 51 and the brush cylinders 74 partially radially inside the slip ring 52 and circumferentially offset to the brush cylinders 73 to arrange.

Be the slip rings 51 . 52 at the in the 3 to 7 shown embodiments attracted by means of an electromagnet, then come the slip rings 51 . 52 in contact with the brush rings 58 . 59 or brush cylinders 73 . 74 and push them against the low starting force of the contacts 66 . 67 away from the stops 64 . 65 ; 77 . 78 , In this case, an electrical contact is made.

The friction pairing of the slip rings 51 . 52 to the brushes 58 . 59 ; 73 . 74 is chosen with a higher coefficient of friction than the friction pairing of the brushes 58 . 59 ; 73 . 74 to the Anfederungs contacts 66 . 67 , This will cause the brushes to rotate due to the rotation of the slip rings 51 . 52 twisted around its own axis. The eccentric arrangement of the brush combination with the rotation leads to a uniform wear of the contact surfaces, so that the stop surfaces are always independent of the state of wear of the brush in a plane of the contact surface.

The carriers, holders or stops for the slip rings or brushes are either formed of an electrically non-conductive material or each electrically insulated from the other components in order not to cause a short circuit.

In 8th is a crankshaft pulley 101 shown in a sectional view. The crankshaft pulley 101 includes a pulley track 102 , which is also referred to as pulley or belt track for short, and serves, for example, to couple a belt of a belt drive with a belt starter generator and / or at least one accessory, such as an air conditioning compressor. The crankshaft pulley 1 is in the drive train of a motor vehicle, as for example in the German patent application DE 10 2007 021 233 A1 is disclosed on a crankshaft 104 appropriate.

In the around a rotation axis 105 rotatable crankshaft pulley 101 is a pulley freewheel 106 integrated. The pulley freewheel 106 is between the belt track 102 and the crankshaft 104 effective. The function of the pulley freewheel 106 will be explained below.

Into the crankshaft pulley 101 is furthermore a Tilgermassenträger 107 integrated. With the interposition of a rubber track 108 is radially outward on the Tilgermassenträger 107 a damper mass 119 appropriate. The absorber mass 119 illustrates a Kurbelwellentilger that serves to unwanted torque fluctuations in the operation of the crankshaft pulley 101 to eradicate and thereby protect the crankshaft from destruction.

The Tilgermassenträger 107 is with the interposition of a washer 109 with the help of a mounting screw 110 at a free end of the crankshaft 104 attached. A screw head of the mounting screw 110 represents an inner ring 111 of Pulley freewheel 106 The pulley freewheel 106 further includes an outer ring 112 that with the belt track 102 connected is.

Between the inner ring 111 and the outer ring 112 of the pulley freewheel 106 are a rolling bearing designed as a ball bearing 115 and designed as a roller bearing bearings 116 arranged. In the axial direction between the two rolling bearings 115 . 116 are freewheel rollers 118 of the pulley freewheel 106 in the radial direction between the inner ring 111 and the outer ring 112 arranged.

Into the crankshaft pulley 101 is further a coupling device 120 integrated, which is designed as an electromagnetically actuated, dry friction clutch and the coupling device 40 in 1 equivalent. The coupling device 120 includes two anchor bodies 121 . 122 , which are designed like a ring and radially inside the belt track 102 are arranged. The anchor body 121 . 122 are spaced apart in the axial direction. The facing surfaces of the anchor body 121 . 122 represent friction surfaces.

The anchor body 121 is by means of rivet fasteners 123 with the interposition of leaf springs 124 rotationally fixed, but limited in the axial direction displaceable on a radial flange of the belt track 102 appropriate. The radial flange 103 extends from the belt track 102 radially inward. The radial flange 103 the belt trace 102 is with the help of other rivet fasteners 128 on the outer ring 112 of the pulley freewheel 106 attached.

The anchor body 122 is with the help of other rivet fasteners 125 with the interposition of leaf spring elements 126 rotatably, but limited in the axial direction displaceable on a holding plate 127 attached, which in turn at the belt trace 102 is attached. The retaining plate 127 extends from the belt track 102 radially inward.

In the axial direction between the two anchor bodies 121 . 122 is the absorber mass 119 arranged with their two friction surfaces. According to an essential aspect of the invention is the absorber mass 119 as electromagnet 130 with a coil 132 executed.

The sink 132 of the electromagnet 130 corresponds to the coil 32 of the electromagnet 30 in the 1 illustrated embodiment. The sink 132 can over the wires 37 . 38 passing through the absorber mass 119 pass through, are energized when the brushes 24 . 25 in contact with the slip rings 8th . 9 come. This contact is made when the anchor 20 during energization of the coil 14 of the electromagnet 10 from the yoke 12 is attracted. The electromagnet 10 is with the help of a mounting flange 144 , for example by means of screws, firmly attached to a crankcase (not shown).

LIST OF REFERENCE NUMBERS

1

Rotary transfer device

4

fixed facility

6

rotator

8th

slip ring

9

slip ring

10

electromagnet

12

yoke

14

Kitchen sink

15

rectifier

16

switch

18

voltage source

20

anchor

21

springing

22

attack

24

brush

25

brush

26

springing

27

springing

30

electromagnet

31

yoke

32

Kitchen sink

34

anchor

35

springing

36

belt track

37

management

38

management

40

coupling device

44

stroke

46

springing

47

springing

48

switch

49

voltage source

51

slip ring

52

slip ring

54

axis

55

arrow

58

brush

59

brush

60

axis

62

holder

64

attack

65

attack

66

Contact

67

Contact

68

switch

69

voltage source

70

arrow

73

brush cylinder

74

brush cylinder

76

holder

77

attack

78

attack

101

Crankshaft pulley

102

belt track

103

radial flange

104

crankshaft

105

axis of rotation

106

Pulley one-way

107

Tilgermassenträger

108

rubber track

109

washer

110

Mounting screw

111

inner ring

112

outer ring

115

roller bearing

116

roller bearing

118

Idlers

119

absorber mass

120

coupling device

121

anchor body

122

anchor body

123

Nietverbindungselement

124

leaf spring

125

Nietverbindungselement

126

leaf spring

127

Halteblech

128

Nietverbindungselement

130

electromagnet

132

Kitchen sink

144

mounting flange

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4009851 A1 [0002]
• DE 9203434 U1 [0002]
• DE 102007021233 A1 [0020, 0048]

Claims (10)

Rotary transmission device for temporarily transmitting a supply voltage between a fixed fixed device ( 3 ) and a rotatable relative thereto rotating device ( 6 ), and with slip rings ( 8th . 9 ; 51 . 52 ), which are temporarily used to transfer the supply voltage with brushes ( 24 . 25 ; 58 . 59 ; 73 . 74 ), characterized in that the slip rings ( 8th . 9 ; 512 . 52 ) or the brushes ( 24 . 25 ; 58 . 59 ; 73 . 74 ) in the axial direction limited displaceable and with an anchor ( 20 ) of an electromagnet ( 10 ) are coupled. Rotary transmission device according to claim 1, characterized in that the slip rings ( 8th . 9 ; 51 . 52 )/To brush ( 24 . 25 ; 58 . 59 ; 73 . 74 ) by at least one spring device in the axial direction of the brushes ( 24 . 25 ; 58 . 59 ; 73 . 74 ) / Slip rings ( 8th . 9 ; 51 . 52 ) are biased away. Rotary transmission device according to one of the preceding claims, characterized in that two slip rings ( 8th . 9 ; 51 . 52 ) are arranged concentrically. Rotary transmission device according to one of the preceding claims, characterized in that the electromagnet ( 10 ) a coil ( 14 ) parallel to the slip rings ( 8th . 9 ; 51 . 52 ) is switched. Rotary transmission device according to one of the preceding claims, characterized in that between the armature ( 20 ) and a yoke ( 12 ) of the electromagnet ( 10 ) a sliding layer is arranged. Rotary transmission device according to one of the preceding claims, characterized in that a stop limit ( 22 ) for the anchor ( 20 ) of the electromagnet ( 10 ) is provided. Rotary transmission device according to one of the preceding claims, characterized in that the electromagnet ( 10 ) a rectifier ( 15 ) is connected upstream. Rotary transmission device according to one of the preceding claims, characterized in that a wear adjustment for the brushes ( 58 . 59 ; 73 . 74 ) is provided. Coupling device with a rotation transmission device ( 1 ) according to any one of the preceding claims. Crankshaft pulley for transmitting a torque between a crankshaft ( 4 ) and a belt drive, with at least one freewheel ( 106 ) and a coupling device ( 40 ; 120 ) according to claim 9.

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